Giovanni Iapichino

Micropropagation of globe artichoke (Cynara scolymus L.) from underground dormant buds (“ovoli”)

SummarySide shoots excised from underground dormant buds ofCynara scolymus L. were used as primary explants to establishin vitro cultures. A 3×3 factorial experiment with all possible combinations of three concentrations (0.5, 1.0, 2.0 mg/liter or 2.22, 4.44, 8.88 μM) ofN6-benzyladenine (BA) and three concentrations (0, 0.1, 0.2 mg/liter or 0, 0.54, 1.07 μM) of 1-naphthaleneacetic acid (NAA) was used to determine the optimum growth regulator combination for shoot multiplication. The highest rate of axillary shoots was induced on Murashige and Skoog agar medium supplemented with 0 mg NAA/liter and 1.0 mg BA/liter (4.44 μM). Other cytokinins tested (kinetin, zeatin, and 2-isopentenyl-adenine were less effective than BA in inducing axillary shoot growth. Up to 60% of elongated microshoots rooted after 5 weeks on 1/2 MS agar medium supplemented with 2 mg/liter (11.42 μM) indole-3-acetic acid (IAA). Seventy percent of rooted plantlets were transferred successfully into soil. Plants are under evaluation for their genetic uniformity and clonal fidelity.

Micropropagation of Metrosideros excelsa

Multiple shoots were induced on stem segments of an 8-y-old plant of Metrosideros excelsa Sol ex Gaertn. “Parnel”. Axillary shoots produced on uncontaminated explants were excised, segmented, and recultured in the same medium to increase the stock of shoot cultures. The Murashige and Skoog (MS) medium, augmented with different concentrations of 2- isopenthenyladenine (2iP) and indole-3-acetic acid (IAA), either singly or in combinations, as potential medium for shoot multiplication by nodal segments was tested. In the following experiment, equal molar concentrations of four cytokinins [2iP, kinetin, zeatin, and N6-benzyladenine (BA)] in combination with equal molar concentrations of three auxins [IAA, α-naphthaleneacetic acid (NAA), and indole-3-butyric acid (IBA)] were tested for ability to induce axillary shoot development from single-node stem segments. The highest rate of axillary shoot proliferation was induced on MS agar medium supplemented with 1.96μM 2iP and 1.14μM IAA after 6 wk in culture. Different auxins (IAA, IBA, and NAA) were tested to determine the optimum conditions for in vitro rooting of microshoots. The best results were accomplished with IAA at 5.71μM (89% rooting) and with IBA at 2.85 or 5.71μM (86% and 86% rooting, respectively). Seventy and 90 percent of the microshoots were rooted ex vitro in bottom-heated bench (22 ± 2°C) after 2 and 4 wk, respectively. In vitro and ex vitro rooted plantlets were successfully established in soil.

Grafting affects yield and phenolic profile of Solanum melongena L. landraces

Abstract The influence of grafting on agronomical and qualitative characteristics of four Sicilian eggplant landraces was investigated. Grafted and ungrafted plants were compared in the open field in the northern coast of Sicily. Solanum torvum seedlings were used as rootstock. Regardless of genotypes tested, grafting significantly increased total fruit production, marketable production, and number of marketable fruits, but did not affect weight of marketable fruits and waste production. Landrace 2 (Sciacca), with black epidermal tissue and pyriform fruit shape, when grafted onto S. torvum not only gave a higher yield performance than ungrafted plants, but also showed a higher phenolic antioxidant content. Landrace 4 (Sicilia), with black epidermal tissue and small cylindrical fruits also benefited, when grafted onto S. torvum, from a substantial increase in antioxidant fruit content. As consumers’ demand for fruits and vegetables rich in compounds important for human health is steadily increasing, these landrace/rootstock combinations should deserve more attention by plant nurseries involved in grafted seedling production and interested in the valorization and conservation of eggplant biodiversity.

Genetic variation and evolutionary analysis of Pepino mosaic virus in Sicily: insights into the dispersion and epidemiology

Pepino mosaic virus (PepMV) is a highly infectious potexvirus that causes a severe disease in tomato (Solanum lycopersicum) crops worldwide. In Sicily, the first outbreak was detected in a single greenhouse in 2005 and it was promptly eradicated. However, in 2008, a large number of greenhouses were simultaneously affected, and it was impossible to eradicate or control the virus. This study addressed the dispersion and the genetic diversity of PepMV isolates obtained from the outbreak in Sicily, in comparison with worldwide PepMV isolates, to gain insight into the factors determining the evolution and epidemiology of the virus. A total of 1800 samples from plants with and without symptoms were collected in the Sicilian provinces of Agrigento, Caltanissetta, Palermo, Ragusa, Siracusa and Trapani. Three isolates collected at different times were biologically characterized. The incidence of the virus increased rapidly from 13% in 2011 to 63% in 2013, and phylogenetic analysis showed that all Sicilian isolates of PepMV belonged to the CH2 strain, one of the six strains previously described. Nucleotide diversity of the Sicilian isolates was low, thus suggesting rapid spread and genetic stability.

Soil Solarization as an Alternative to Methyl Bromide Fumigation for Annual Strawberry Production in a Mediterranean Area

ABSTRACT This study compares the effects of soil solarization and methyl bromide fumigation on the growth and yield of strawberry plants (Fragaria xananassa Duch.) cultivated under plastic tunnel conditions. The study was conducted in a Mediterranean coastal area, in four consecutive annual production cycles in a field with no history of methyl bromide fumigation and 2-year history of strawberry production. In all 4 years, solarization was conducted for 7- to 9-week intervals from late June to early September. Cultivar Tudla frigo-plants were planted through mulch in the first week of September of each year. Average daily soil temperatures in solarized plots measured at 15 cm depth were 6.0, 8.1, 7.8, and 8.4 °C higher than the control, during Summer 2001, 2002, 2003 and 2004, respectively. Solarization produced 781, 610, 630, and 525 hours above 37 °C at 15 cm depth during the first, second, third, and fourth year, respectively. In the first year, solarization significantly increased both early and total marketable yields by 15% compared with the fumigated plots, whereas in the successive years, solarization and fumigation were equally effective in increasing yields when compared to untreated plots. No significant differences in average fruit weight were observed between solarized and fumigated plots in individual years. The study demonstrated that the Mediterranean coastal areas have appropriate environmental conditions to apply soil solarization in strawberry planting as a viable substitute to methyl bromide fumigation.

IMPROVED MICROPROPAGATION IN POLYGALA MYRTIFOLIA

SummaryStem segments from apical shoot tips of Polygala myrtifolia were used as primary explants to establish in vitro cultures. Axillary shoots produced on non-contaminated explants were excised and recultured in the same medium to increase the stock of shoot cultures. Equal molar concentrations of five cytokinins [2-isopentenyladenine, kinetin, zeatin, N6-benzyladenine (BA), and adenine] were tested for ability to induce axillary shoot development from double-node stem segments. The highest rate of axillary shoot proliferation was induced on Murashige and Skoog agar medium supplemented with 1.8 μM BA. Seven indole-3-acetic acid (IAA) concentrations (0, 2.9, 5.7, 8.6, 11.4, 14.3, 17.1 μM) were tested to determine the optimum conditions for in vitro rooting of microshoots. Up to 72% of the microshoots rooted with 14.3 μM IAA. Other auxins tested, α-naphthaleneacetic acid and indole-3-butyric acid, were less effective than IAA in inducing adventitious root formation. All rooted plantlets having more than three roots were successfully established in soil.